Countdown to Launch

During the days remaining till the 15th of
July, Lunney and Bushuyev kept in touch by telex and telephone. On 23
June, Lunney sent the "Launch minus 21 days" report to the
Professor:

SPACECRAFT:

S-IB launch vehicle stage fuel (RP-l)
loading was completed satisfactorily on July 23, 1975. Countdown
demonstration test preparations have started and the nine-day test
will start at 0700 EDT on June 25, 1975.

GROUND SYSTEMS:

ATS-6 satellite testing is complete. All
MCC-H network interface testing is complete except for S-band
tracking test to be conducted on June 25, 1975.65

[313] Three days later,
Lunney and Bushuyev discussed a variety of topics, including the
joint control center simulations scheduled for the end of the month
and some public affairs questions.66 Meanwhile, the astronauts continued their
training.

At 2:50 on the afternoon of the 24th, the
prime crew began a three-week preflight medical isolation program -
the "Flight Crew Health Stabilization Plan." Stafford, Slayton, and
Brand were limited to specific working and training areas at JSC, and
only previously screened personnel could come in contact with them.
These "primary contacts" were required to wear surgical masks when in
the presence of the crew. No one, especially the three astronauts,
wanted a change in crew assignments because of the sniffles or any
other common illness. In their off-duty hours, the prime three were
quartered in mobile homes near the astronauts' gym in the northeast
corner of the space center. In addition to further practice in the
simulators, they continued their work on Russian.67 (See table X-1.)

Table X-1. ASTP Crew
Training Summary as of 15 July 1975

Training activities

Hours accomplished

Stafford

Brand

Slayton

Briefing/reviews:

Command and service module

26.4

55.6

60.3

Docking module

8.0

21.5

24.9

Launch vehicle

2.6

3.0

2.6

Experiments

94.8

95.8

100.3

Flight plan/checklist

13.5

38.0

19.5

Mission technique/rules

29.5

61.0

23.5

Soyuz

2.0

2.0

2.0

Systems Training:

Transfer procedures

17.5

27.0

17.5

Crew systems

18.5

27.5

22.5

TV

2.5

5.0

5.5

Photo

12.5

12.5

11.0

Experiments

81.3

82.3

117.5

Stowage

1.0

2.0

7.0

Bench checks

12.0

12.0

12.0

Egress/fire

13.0

13.0

13.0

Spacecraft test

106.5

98.5

174.5

Morehead planetarium

0.0

0.0

12.5

Medical

33.5

22.5

31.5

Simulators:

Command module simulator/docking
module simulator

428.0

474.2

549.3

Command module procedures
simulator

32.5

0.0

56.0

Russian language

1,016.5

923.5

1,077.5

Joint crew activities

737.6

812.3

735.1

Total hours

2,689.7

2,789.2

3,075.5

[314] On 25 June, the
Countdown Demonstration Test (CDDT) began at 7:00 a.m. After
participating in the "Joint Orbital Operations Simulation" between
the Houston and Moscow control centers, which began early on Sunday
the 29th and continued for 56 hours, the prime crew departed Houston
on 2 July for KSC, where they would take part in the manned portion
of the CDDT. During one phase of the test that included a simulated
ignition and lift-off, Vance Brand's space suit leaked, as it had
during a high altitude test run. This time the problem was traced -
to one of the pressure-sealing slide fasteners. A minor modification
to this "sophisticated zipper" fixed the leak, and technicians also
altered Stafford's and Slayton's suits as a precautionary measure. As
time ticked away toward the hour of launch, the tempo of activities
quickened.68

After a one-day holiday and an additional
check of Brand's suit, the prime crew flew their T-38s back to
Ellington Air Force Base on Saturday, 5 July. That afternoon, they
reviewed the flight data file, and on Sunday they took to their T-38s
again and later practiced Russian. As last minute checks went on at
the Cape, the crew spent a busy week in the command module simulator.
Rendezvous was practiced, with and without systems failures thrown in
by their instructors, and solutions to possible docking malfunctions
were studied and worked out in the simulator. On 13 July, the crewmen
once again climbed into their jets and departed for
Florida.69

Reports from Baykonur Cosmodrome
indicated that the Soviet crewmembers were also in quarantine. After
talking to Stafford on the 10th, Leonov and Kubasov continued
reviewing their flight plans at the Soviet launch center. While they
studied, the launch crews readied the two space vehicles. The prime
spacecraft and booster were on the pad and fueling began on the 11th.
Two days later, the second Soyuz and launch vehicle were transported
to the secondary pad some 20 kilometers distant. All preparations
were on schedule, and Soviet mission control advised the Americans
that the tracking stations and tracking ships Akademik Sergei Korolev
and Kosmonavt Yuri
Gagarin were ready for the
flight.70

Since the personnel of the Soviet and American
control centers were scheduled to start round-the-clock duty
scheduled on 14 July, 24 hours before the launch of Soyuz, the teams
of visiting specialists had to be in place ahead of time. A group of
15 specialists and interpreters from the Soviet Union had arrived in
Houston on the 8th.* NASA's flight control...

[315]

The Soyuz launch vehicle and ASTP
spacecraft are transported to the launch site by railroad flat car
(Soviet Academy of Sciences photo).

....specialists led by Charles R. Lewis
arrived at Moscow Sheremetyevo Airport on the 12th, where they were
met by V. G. Kravets, V. D. Blagov, and S. P. Tsybin, members of the
Soviet ground control teams.** With everyone in place, Chet Lee conducted the "L - 2
Day Review" to determine whether all systems were set for
launch.71 Gulick could give a reasonably favorable weather
forecast - broken clouds, wind out of the east southeast at 10 knots,
a temperature of about 29°C, with about a 70-percent change of
thunderstorms. All stations reported that they were ready to
go.

During CDDT, excessive leakage was
discovered in the suit loop of the spacecraft while in the low
pressure (vent) mode, although no leakage was evidenced at high
pressure (3.75 psi). Troubleshooting conducted in the spacecraft
isolated the problem to Astronaut Brand's suit. Following completion
of CDDT, Astronaut Brand's flight suits were returned to JSC where
additional failure analysis established the source of this low
pressure leak to be in the crotch radius area. The leak is induced
when the crewman is tightly strapped into the couch position causing
the zipper sealing lips to unseat. After examining several possible
corrective concepts, a zipper insert [made of vinyl tubing] was
designed which can be placed between the sealing zipper and the
donning assist zipper thereby preventing the sealing lips from being
unseated by the couch position condition. Certification tests of the
zipper insert have been conducted to verify its acceptability for
flight and to assure no adverse effects on use of the suits in the
pressurized mode. Vance Brand had also fit checked his suits with the
insert installed to verify acceptability.